At age 9, young Alvy Singer is too intellectual for his own sake to the point of having a nervous collapse while doing his homework. "The universe is expanding" he says to his therapist once his family realizes Alvy doesn't want to do anything anymore because he's afraid of the world and the universe. With such dimensions, a young star rose to prominence in the Oscar winning classic Annie Hall (1977). Jonathan Munk plays the young version of Woody Allen's character and that marks as his only film role.

His brother Robert Munk is also an actor and they share the distinction of playing younger versions of Woody Allen on film: Robert appeared in Stardust Anıları (1980) as the young Sandy (Allen's character). It's also his only film role to date.